Sheet or signature feeding machines

ABSTRACT

A FEEDER FOR SHEETS OR SIGNATURES, FEEDING FROM A SUPPLY HOPPER TO A CONVEYOR, IS CONSTRUCTED TO HAVE A SINGLE EXTRACTING CYLINDER OPERATING BETWEEN THE SUPPLY AND THE HOPPER, EFFECTIVE TO FEED TWO SHEETS PER CYCLE OF REVOLUTION. A SHEET RELEASED FROM THE EXTRACTING CYLINDER IS SETTLED ON THE CONVEYOR BY MEANS OF AN AIR BLAST. FURTHER, THE ARRANGEMENT MAKES POSSIBLE AN IMPROVED SYSTEM FOR DEMOGRAPHIC SIGNATURE GATHERING.

Feb. 20, W B McCAlN EVAL 3,717,337

SHEET OR SIGNATURE FEEDING MACHINES Filed April 27, 1970 4 Sheets-Sheet l Fig Z 6 B- Poc KET eo 3T' l l Inventors william. B. Mc Cain James F. Cosrove Edward LZagorSkL Feb. 20, W'B' McCAlN ETAL v 3,717,337

SHEET OR SIGNATURE FEEDING MACHINES Filed April 27, 1970 4 Sheets-Sheet 2 ALL S- E F POCKET POCKET P CNVEYR`I5 ZNHClrn B. MC Cain. 3M-L@- James Filosrove W11 Edward J. zngofski BOOKS To STITCHER d tteorn Feb. 20, W, B. MCCAN ET AL SHEET OR SIGNATURE FEEDING MACHINES 4 Sheets-Sheet 3 Filed April 27, 1970 Inventors w llam. B. McCain, James F-Cps3rove d www 34a im a @f KM Feb. 20, W, B MCC/MN ET AL SHEET OR SIGNATURE FEEDING MACHINES 4 Sheets-Sheet 4 Filed April 27. 1970 lni/enots' William. j/IECCQQ James 1;.l Clsrove Edward J. Zegers k1' B Kw ,Um auf( Zit/kwil.'

l-ttornes United States Patent 3,717,337 SHEET 0R SIGNATURE FEEDING MACHINES William B. McCain, Hinsdale, James F. Cosgrove, Western Springs, and Edward J. Zagorski, Chicago, Ill., assignors to McCain Manufacturing Corp., Chicago, lll.

Filed Apr. 27, 1970, Ser. No. 32,257 Int. Cl. B65h 3/08, 5/12, 29/24 U.S. Cl. 271-13 3 Claims ABSTRACT 0F THE DISCLOSURE This invention relates to sheet handling apparatus and in particular to machines for gathering signatures, a signature being a folded sheet that is to become part of a book such as a magazine.

Signature gathering machines are primarily of two kinds. There is the saddle gatherer in which the sheets of the signatures are spread apart and dropped on a support which is in the form of two plates forming an inverted V from which the saddle designation is derived. This saddle support extends past the hoppers or pockets from which the signatures are fed, and a conveyor chain presenting feeder pins moves along a slot at the top of the saddle support in such fashion as to move the first signature on the saddle support to the second pocket where the second signature is gathered atop the first one, the procedure being repeated at each successive pocket until all the signatures comprising the book have been gathered one atop another. The signatures thus gathered by the saddle type gatherer have their backbones or folds nested one in another and are joined by staples applied colineally with the fold line at the backbone of the book. A magazine thus produced is the familiar one where the piercing ends of the joining staples are revealed when the magazine is spread at the center. In effect the staples penetrate only half the pages.

The other principal type of signature gatherer, the flat gatherer, is characterized by feeding the signatures in flat form, on their sides, so to speak, to a conveyor. Again, the conveyor moves past the pockets which contain the signatures, and the signatures are fed out of the pockets as the conveyor moves therepast so that the signatures are collected one on top of the other. In the instance of flat gathering, the backbone of the signatures, instead of being nested one inside another, are juxtaposed one on another to present a square back .rather than a V-shaped back for the book. The signatures are joined somewhat differently in that the staples penetrate the book from front to back, transverse to the backbone.

The present machine is of the flat gathering type in that the signatures on the conveyor are in a flat state rather than with the sheets or pages spread apart as in the instance of saddle gathering.

Previously, and to the best of our knowledge, there have been two forms of flat gathering machines for signatures. The more traditional one is the so-called arm gatherer in which an oscillating arm having a gripper thereon withdraws the signature from a pocket and then drops the signature on the conveyor. A very complex mechanism is required in order to account for reliable operation, and in effect one-half of a cycle is lost in that Mice the arm accomplishes no useful work during that part of the machine cycle in which it returns to the pocket to grab the next signature or sheet. This objection to the arm gatherer is obviated by the other type of at gatherer in which a gripper on a cylinder extracts the signature from its pocket and transfers it to a second cylinder in one-half cycle of revolution. In the second half-cycle of the same or first cylinder, a second signature is withdrawn from the pocket and is transferred to the second cylinder, and during the same second half-cycle the second cylinder is depositing the first signature fed thereto on the conveyor. In effect, and for all practical purposes, no time is lost because when a sheet is moving from the first cylinder to the second cylinder, the first cylinder is ready to pick up a second sheet so that two sheets are transferred in one cycle. Nonetheless, a great deal of space is required in that there are two cylinders between the pocket and the conveyor, and the signature needs t0 be transferred from one cylinder to another before being dropped on the conveyor.

The primary object of the present invention is to so construct a flat gatherer as to require minimum handling of the sheet being transferred between the pocket and the conveyor, while utilizing to maximum advantage the whole cycle of the mactine to complete transfers. As will be shown, two sheets are transferred in one cycle, and yet only a single cylinder is used between the pocket and the conveyor. In effect, then, we combine the advantages of the two known kinds of fiat gatherers while eliminating the disadvantages, and so to do constitutes another object of the present invention.

Specifically, it is an object of the present invention to construct a flat gatherer of unusual form characterized as follows: A cylinder rotates between the conveyor to which the signatures or sheets are to be delivered and the pocket or hopper which contains the supply. The cylinder carries two grippers spaced substantially apart so that a sheet is Withdrawn from the pocket in each half-cycle of the machine, a cycle being defined as 360 of rotation of the cylinder. The sheet withdrawn from the pocket is moved downwardly along an arcuate path represented by the rotation of the cylinder until it attains a releasing position just above the conveyor at which point the gripper is opened and the sheet released. (At about this time the second gripper withdraws the second sheet from the pocket.) The released sheet is forced downward onto the conveyor by a blast of air directed against the upper side of the sheet.

By so constructing the machine, it is possible to transfer sheets at an exceptionally high rate. The rate in fact is so high that the following circumstances prevail: A sheet dropped on the conveyor is moved forward by feeder pins on the conveyor which engage the trailing edge of the sheet delivered thereto. A second sheet may be delivered to the conveyor from the same pocket, and the second sheet will immediately trail the first sheet, being fed forward with the conveyor by its own set of feeder pins on the conveyor. The machine `may deliver signatures or sheets of a length of 111A inches, and yet the spacing between adjacent sets of pins need only be 12 inches. This is a very small tolerance, and yet no problem has been encountered in maintaining the speed. In fact, the rate of delivery is so fast that a sheet being dropped on the conveyor must be dropped atop the feeder pins which are already in engagement with the trailing edge of the previous sheet, which is to say that the signature when released for delivery to the conveyor must lead the feeder pins assigned thereto precisely in the manner that an aim on a fast moving target must lead the target significantly when the shot is fired if the projectile is to intercept the target.

As noted above, the books produced by gathering signatures one on top of the other may be in the form of magazines. In fact the present invention may have its greatest utility in terms of gathering signatures for magazines in a demographic sense. What we mean by demographie gathering of a signature is this: The magazine publisher may produce different forms of the same edition, which is to say that the production of the weekly edition may involve a variance in context either in geographic terms of vocational terms, or both. Thus the magazines intended for Midwest U.S.A. reading may have text matter differing from the same edition to be mailed to readers in the Southwest U.S.A. The difference may only be advertisements, but in any event demographic gathering assumes that the signatures contained in one pocket of the machine may or may not be delivered for the book being compiled. There may be variance in the same demographic sense for professions or vocations: housewives are to get a cake mix recipe whilst all unmarrieds are to get a travel advertisement.

The conveyor used to gather the signatures is usually exceptionally long. There may be as many as fifty or sixty pockets arranged in a row parallel to the path of the conveyor. This requires a great deal of floor space, and therefore another object of the present invention is to considerably reduce the amount of oor space required for demographic signature gathering. Specifically, this object is achieved by placing at least some of the feeder pockets in tandem, themselves feeding signatures selectively (e.g. demographically) to a side conveyor f which moves the signatures to the main conveyor. The

main conveyor is where the signatures are gathered into the book, and it may be characteristic of either a hat gatherer or a saddle gatherer. Thus, under this object, there will be at least two pockets in tandem, one containing an A signature and one containing a B signature. One of these signatures, or neither one, may be required for the book being compiled. This arrangement of tandem pockets, feeding to a secondary conveyor transverse to the main primary conveyor on which the signatures are gathered, will be repeated in many rows transverse to the main conveyor.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration show preferred embodiments of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be made as desired by those skilled in the art without departing from the present invention.

In the drawings:

FIG. l is a perspective View of a signature gathering machine constructed in accordance with the present invention;

FIG. 2 is an enlargement of a portion of the struct-ure shown in FIG. 1;

FIG. 3 is a fragmentary perspective view substantially on line 3-3 of FIG. 2;

FIGS. 4 and 5 are schematic views showing an extension of the present invention;

FIG. `6 is a sectional view on the line 6--6 of FIG. 2;

FIG. 7 is an end elevation on a reduced scale substantially on the line 7 7 of FIG. 2;

FIG. 8 is a detail elevation showing the sheet grippers; and

FIG. 9 is a fragmentary elevation similar to FIG. 8 showing the manner in which the sheet grippers are operated.

While the present machine, FIG. 1, is disclosed herein in terms of flat gathering of signatures in a demographic sense, either from an A pocket or a B pocket, nonetheless the principles may be applied to a single hopper, the B pocket, FIG. 2, containing a supply of sheets to be fed 4 rapidly to a conveyor. Since the construction and operating principles are identical for both feeder pockets, whether signatures are fed or plain sheets are fed, We will tirst describe in detail the B. pocket arrangement and then we will describe how the invention may be used for demographic signature gathering.

The supply of sheets will be contained in a forwardly and downwardly inclined hopper 10, FIG. 6, characterized by a bottom support plate 12 and a forward stop plate 14. The bottommost sheet in the stack is to have the leading edge thereof presented to one of two gripper means 20-1 and 20-2, FIG. -8. The gripper means 20-1 are carried on a rock shaft 22-1, and the gripper means 20-2 are carried on a rock shaft 22-2, FIGS. Z and 8 which rotate with a cylinder or disc 25, of which the-re are two, FIG. 2, constituting the extracting cylinder. Advantageously the sheet is presented to the gripper by a suction cup 26 supplied by a conduit 27.

Before describing in detail the distinctive structure and functional characteristics of the present invention, it is appropriate to consider the known construction and operation of the gripper fingers 20-1 and 20-2 carried by the discs 25. -Each such finger and its associated parts are identical, and attention is now directed to FIG. 8 wherein it will be observed that each tinger or gripper is normally in an open position with respect to a flat anvil or plate 28 carried on the disc 25. This is the condition prevailing at the time a gripper finger is approaching the exposed edge (or backbone) of the sheet (or signature) adjacent the front of the supply hopper 10, but the concurrent event is that the gripper iinger is then tobe moved immediately to a closed position to clamp the edge of the sheet to the opposed anvil surface 28. It will be appreciated that this is an accurately timed operation as will be apparent from the description to follow.

There is a gripper finger on one disc 25 directly opposite and paired with an identical gripper finger on the other disc as shown in FIG. 2. Each gripper finger is supported by a bracket 29, FIG. 8, which in turn is clamped to the related rock shafts 22-1 and 22-2 carried by and extending between the discs 25. The supporting rock shafts extend parallel to the main drive shaft 30 to which the discs 25 are keyed or otherwise aixed for rotation therewith. Thus, rotation of the shaft 30, through a drive chain 31, FIG. 3, is effective to rotate the discs 25, and the rock shafts which carry the gripper finger assemblies are carried along in a planetary sense.

A third disc 25-3 is carried by shaft 30, FIG. 2, and this disc carries means including gears for oscillating the roc-k shafts 26-1 and 26-2 which support the grippers, as will now be described.

Each rock shaft is provided at one end, outboard of disc 25-3 with a pinion gear 29, FIGS. 8 and 9, as mentioned. Each pinion is meshed with a segment gear 33. Each such segment gear 33 is pivotally supported on a stub shaft 34, FIG. 9, supported on the left-hand side of disc 25-3 as viewed in FIG. 2, and is biased by a spring 35 anchored at one end to a pin 36 on the segment gear and at the opposite end to a projecting ear 38 on a hub element 39 keyed to the disc 25-3 for rotation therewith. This arrangement prevails for each segment gear.

Each segment gear as 33 has a cam follower 40 thereon located between the pivotal mounting of the segment gear and the end thereof presenting the segment gear teeth. The cam followers 40, of which there are two, one for each of the segment gears, travel in a revolving sense about and in contact with a stationary cam 41, FIG. 9, mounted on the inside face of the side plate of the machine. The general contour of this cam presents a long lobe 41L and a shorter dwell 41D, FIG. 9.

Each spring 35 is effective, when the follower 40 rides on the cam dwell 41D to pivot the segment gear inward toward the axis of disc 25-3 imparting rotation to the pinion 29, causing the gripper nger as 20-2 to pivot in a closing direction toward the related anvil 28. This action takes place at a time when a signature or sheet as S1, FIG. 8, is in temporary holding position, presented by the suction cup, whereupon the two activated fingers 20-2 (one on each disc 25) grab the presented edge of the thus positioned sheet and transfer the sheet from the supply hopper to the extracting cylinder. Continued rotation of the extracting cylinder carries the sheet along until the cam follower of the activated gripper nger encounters the lobe 41L of the cam 41, FIG. 9, whereupon each corresponding segment gear is oscillated in a direction opposite to that induced initially by the spring v35, manifest in an opening movement of the gripper finger which releases the signature.

It was mentioned that the suction cup 26 (of which there may be as many as six) is supplied by a conduit 27. The suction cups 4are carried on 'a support bar (not shown) supported for swinging motion on a rock shaft 40, FIG. 6. The rock shaft 40 at one end is provided with a depending arm 42, having a cam follower 43 tensioned against a cam 44 by a spring 45, The cam is fixed to shaft 30 to rotate therewith, and has a lobe 44L, there being two such lobes 180 apart, FIG. 7.

When a lobe 44L is presented to the cam follower 43 the rock shaft 40 is rocked clockwise as viewed in FIG. 6 shifting the suction cups upward to engage the underside of the lowermost sheet or signature in the hopper and concurrently vacuum is established in the suction cups 26. Resultantly the suction cups 26 are effective to pick up the exposed portion of the lowermost sheet in the hopper 10. When the dwell or low part of the cam 44 is presented to the follower 43 as shown in FIG. 6 spring 45 is effective to turn rock shaft `40` in the opposite direction, pulling the suction cups 26 downward so that the leading edge of a sheet or signature as S1, FIG. 8, is in position to be grabbed by a gripper. The supply of vacuum is then discontinued.

In some instances it may be advantageous to aid the effectiveness of the grippers by lifting the pile of signatures or sheets in the hopper substantially concurrent with the grippers as 20-1 or 20-2 as the case may be, withdrawing the bottommost sheet, presented by the suction cups 26. To thus lift the remainder of the pile or supply is not always necessary, but the present machine is equipped to so do, and referring to FIG. 6 a plurality of pile separator fingers 50 have inner beveled ends presenting relatively sharp points adapted to penetrate the supply of sheets to separate the bottommost sheet from the remainder of the supply above. Thus the separator fingers are to have a horizontal inner stroke and a'n upward vertical stroke, and to this end the separator fingers are supported from a vertically shiftable rock shaft 51, FIG. 2.

Each finger 50 projects inward from the lower end of a support arm 54, and the upper end of the support arm is provided with a clamp head 55 which is clamped to the rock shaft 51. The ends of the rock shaft 51 are supported in square guide blocks as 55, FIG. 3, confined for vertical motion in elongated guideways 56 formed in the side plates of the machine. Coil springs 57 in the guideways 56 apply tension to the guides 55, normally tending to bias the latter to a lowermost position in the guideways 56 characterizing the at-rest condition of the separator fingers 50.

The end of each rock shaft 51 is also provided with an arm 60 secured thereto, FIGS. 3 and 6, and the free end thereof is tensioned by a coil spring 61, FIG. 3, s that a cam follower 62, FIG. 2, on an arm 63 clamped to the rock shaft 51 is normally held against a cam 65. Cam 65 is secured to a cam shaft 66, and referring to FIG. 3 cam shaft 66 is provided with a sprocket 67 adapted to be driven by a chain (not shown).

The cam shaft 65 also carries a pair of cams 70 engageable with followers 71 on rock shaft 51, and the cams 70 are effective to raise and lower rock shaft 51 guided by the blocks 55 in the guideways 56.

Cam 65, on the other hand, is adapted to produce oscillation of rock shaft 51 characterizing in and out motion of the pile separator fingers 50.

The timing arrangement is such that just after the suction cups 26 have been effective to pull the bottommost sheet or signature downward to present it to the grippers on the extracting cylinder, the pile separators 50 are moved inward and then upward to take the weight of the pile off the sheet being withdrawn by the grippers in their closed position on the anvils 28.

Referring to FIGS. 6 and 8, it will be appreciated that a sheet withdrawn from the hopper moves downward with the turn of the extracting cylinder along an arcuate path. The signature thus withdrawn is to be deposited on a conveyor 75 characterized by longitudinally spaced sets of feeder pins 76-1, 76-2, and 76-3, FIG. 2. The spacing between the pins is slightly greater than the length of the sheet to be dropped on the conveyor between the sets of pins. For example, the sheets may be 11% inches long and the spacing between the pins only 12 inches, so it becomes crucial to high speed operation to deposit the sheet accurately in the space assigned thereto on the conveyor. Assuming for example that in the sequence of operation, FIG. 2, three sheets are t0 be fed from the hopper 10, one after another, the first sheet would have its trailing edge engaged by the pins 76-1, the second sheet by the pins 76-2, and the third sheet would be fed by the pins 76-3.

A cycle of the machine is defined as a 360 turn of the extracting cylinder represented by the discs 25. There are two sets of grippers within the 360 circumference of the extracting cylinder, and hence two sheets may be extracted from the hopper 10 per cycle of revolution. Therefore, three sheets would be fed in one and onehalf cycles.

The feeder or conveyor pins are carried on endless chains 78 and move in elongated slotsas 80 provided in a support table 81, FIG. 6. The drive means for turning the chains need not be described, inasmuch as any convenient mode may be employed, constituting no part of the present invention.

Under and in accordance with the present invention, the sheets are deposited accurately in the assigned area on the conveyor by making provision for a radially directed air blast against the upper side of the sheet so that it in effect is forcefully driven downward toward the support table 81. In accomplishing this, we provide a plurality of air tubes including a long tube 85, and a shorter tube 86, FIG. 6, positioned close to the discs 25. The tubes and 86 are supplied constantly with air under pressure from a header 87, and each is provided with a plurality of openings 89 in alignment along the arc at the underside of the tubes. Advantageously, there are a pair of such tubes associated with each of the discs 25 constituting the extracting cylinder as best shown in FIG. 2, although more may be employed.

Experience shows that a long tube and a short tube in combination produce reliable and consistent results. Additionally, we have found that a superior performance is achieved by having the air tubes 85 and 86 bent on arcs having a radius slightly less than the radius of the extracting cylinder.

The releasing point of the signature is near the bottom of the extracting cylinder, FIG. 6, which is to say that when the edge of the sheet held by the grippers is approximately at the position, FIG. 6, the grippers are opened. Escape of the sheet is prevented by an adjustable register gauge or stop 90, FIG. 6. The released sheet is in a floating condition, in which state the air blast from the tubes 85 and 86 in effect amounts to a hand (or two hands) forcing the sheet downward into its assigned area. Nonetheless, the timing and orientation is such that when the sheet faills onto the feeder pins,

the front or leading portion of the sheet (considered in terms of the forward movement of the feeder pins) falls atop the pins which are in leading position, the sheet then drifting into the area immediately therebehind. Thus, and referring to FIG. 2, if the sheet is to be in the area between pins 76-2 and 76-3, eventually to be fed along by the pins 76-3, then this sheet, when released, will actually fall with its leading portion atop pins 76-2.

It will be seen from the foregoing that the sheet feeder of the present invention is somewhat unusual in that the sheets are deposited in a fiat state on a longitudinally movable conveyor by means including a transfer or extracting cylinder which extracts two sheets or signatures from a hopper per cycle of revolution. No intervening cylinder is required insofar as concerns transfer of sheets from the hopper to the conveyor. If the disclosure be confined or restricted to what is shown in FIG. 2, cornpared to the tandem arrangement shown in FIG. 1, the machine may be viewed as an unusual form of sheet feeder for feeding sheets from a hopper to a conveyor at a high rate of speed. However, the principal form of utility of the present invention may be in connection with signature gathering, in which event there will be two machines in tandem or side-by-side relationship as shown in FIG. 1, respectively affording an A pocket and a B pocket, operating independently, but feeding signatures selectively to the feeder pins of the conveyor. The two machines are identical in construction, and operate precisely in the manner as described in detail.

Attention is therefore directed to an extended consideration of the A pocket-B pocket arrangement of FIG. l, more extensively considered in FIGS. 4 and 5.

In FIG. 4, the reference character SD identifies a so-called saddle gatherer or conveyor as the primary conveyor on which signatures are collected to form books. However, the primary conveyor may also be a flat gatherer or conveyor, and the saddle conveyor SD has been selected only to demonstrate that the present invention in its extended form is applicable to either a saddle gatherer or a liat gatherer for collecting the signatures into a book.

The ordinary circumstance prevailing in connection with magazine publishing is that the hoppers or pockets which contain the signatures are arranged in side-by-side relationship, one next to the other, along the length of the prim-ary conveyor as SD. Thus, in the normal arrangement the pockets or hoppers A, B, Y, Z, FIG. 4, will be strung out along the length of the saddle conveyor SD, and in the instance of demographic gathering the hoppers or pockets are selectively controlled to feed a signature which is to be part of the |book being compiled. The normal arrangement can occupy a great deal of floor space, but under the present invention the length is considerably reduced in the direction of the primary conveyor.

Thus as shown in FIG. 4, the A pocekt and B pocket tandem arrangement is repeated many times over: C, D; E, F; and so on through the alphabet, terminating say at the paired feeders Y, Z. This amounts to twenty-six pockets, two in a row making thirteen rows. lEach pair of pockets or hoppers feeds a conveyor 75, precisely in the manner in which this has been described in detail in connection. with FIG. 2, noting that the secondary conveyors 75 project at right angles to the length of the saddle conveyor SD. Thus, the saddle conveyor may be viewed as the main :stream of collected signatures, and the secondary couveyors 75 may be Iviewed as tributaries of the main stream.

Consideration may now be given in the manner in which a book will be compiled from the signatures in a demographic sense. The paired pockets, FIGS. 4 and 5, may be arranged in tandem in the manner shown in detail in FIG. 1. The A pocket, for example, will only feed signatures S1, and the related B pocket will only feed signatures S2. Pocket E feeds S5 signatures, pocket F feeds S6 signatures, and so on.

The signatures on a conveyor 75 are moved forward to a signature transfer apparatus 210 which is characteristic of the saddle type gatherer, noting that a signature S6, FIG. 5, has been fed from pocket F. Also, as shown in FIG. 5, the transfer apparatus 210 includes a transfer cylinder 211 having a gripper 212 thereon adapted to clamp the backbone of the signature, FIG. 5 (as is well known in the art), and the signature thus picked up by cylinder 211 is released to a back register gauge RG. The signature is transferred from the register gauge RG to an extracter cylinder 213 having a gripper 214 thereon which clamps the lap of the signature in the register gauge and extracts it therefrom. An opening cylinder 216 is opposite the cylinder 213 and is provided With an opener finger 217 which moves between the two sheets of the signature carried by the cylinder 213 to spread the sheets so that the latter will straddle the saddle SD when released by the cylinders 213 and 216.

FIG. 5 shows several different stages in the collection of signatures to compile the book. The signature S1 has al ready been deposited on the saddle conveyor SD. This signature S1 has been earlier fed from the A pocket. It will be noted in FIG. 5 that the siganture (S3) next to become part of the book SG is in the register gauge ready to be extracted by the gripper 214. Thus, signature S1 has been moved by the conveyor to the extractor unit 210 associated with the two pockets C, D and a signature S6 has been fed from F pocket to its conveyor 75 in the process of being advanced to the associated transfer apparatus 210. The book being compiled, containing signatures S1, S3, and S6 is not to contain signatures S2, S4, and S5. When all the signatures have been collected for 'a single book, the book is in condition to be stitched, FIG. 4.

Thus, it will be seen that the present invention has many ramifications, and in this connection it may be observed that the form of the invention considered in iFIGS. 4 `and 5 assumes that the conevyor 7S extends parallel to the axis of shaft 30. However, it is possible to alter the arrangement so that the conveyor 75 travels along yan axis lat right angles to the axis of each pocket of shaft 30, in which event one pocket will be in front of the other rather than in the sideJby-side relationship shown in FIG. l.

In the form of the invention shown in FIG. 1 and contemplated by FIGS. 4 and 5, it will be recognized that the primary conveyor can accept signatures from both pockets A and B provided that the cylinders 2S associated therewith `are in phase, in which event (and referring to FIG. 4 for the moment) a signature S1 would be delivered to the conveyor 75 from pocket A concurrently with `a signature S2 being delievred to conveyor 75 from pocket B. Of course, the transfer apparatus 210 must be phased or timed appropriately to receive the signatures being delivered thereto at the terminus of each related tributary conveyor 75. However, it may be noted that in most instances the arrangement will be such that for any given book a signature is to be fed from either A pocket or B pocket or neither pocket, and in no event will signatures be fed concurrently to the conveyor 75 from both pockets.

Of course it becomes necessary to control the pocket feed in the sense of feeding or not feeding a signature depending upon the content of the book being compiled. Insofar as a feed or no-feed command signal can be concerned, we can Iadopt the disclosure in co-pending application Ser. No. 841,493, filed July 14, 1969, which is to say that the delivery suction cups 26, FIG. 6 hereof, may be latched in an ineffective position when a signature is not to be delivered from the related hopper.

It will be seen from the foregoing that the pocket feeder of the present invention, FIG. 2, possess utility of different orders in that it may be used as a high rate sheet feeder or it may be combined with fa second pocket, FIG. 1, for feeding sheets selectively to a main conveyor, signatures or otherwise. Further, while the present machine itself is definitely a flat gatherer in terms of signature feeding, it can nonethelesss be used to feed the tributary conveyor selectively with signatures which are to be compiled by another gatherer, FIGS. 4 and 5, `which may be a saddle gatherer or a fiat gatherer.

In any event, high speed operation is attained by using a blast of air from a tube bent substantially concentricaliy to the extracting cylinder. In retrospect this is understandable in that the released sheet on the extracting cylinder is itself lan arc at the time of release, so the air blast used to settle the released sheet on the conveyor is itself a cornplement of the shape of the released sheet. Further, the air blasts emitted from the openings 89 represent radial jets as shown yby the radial arrows in FIG. 6, characterizing an air pattern which is the complement of the shape of the sheet in its released state.

The short tube 86 supplements the long tube 85 which is to say that the openings in the short tube overlap the same number of openings in the long tube, and this is important in stopping the momentum of the released sheet, which is to say that the released sheet tends to drift toward the gauge 90 which extends in a plane parallel to the conveyor axis, but the supplemental blast of air from the short tube, supplementing that from the long tube, nullifies the drifting tendency of the sheet and causes it to settle immediately on the conveyor without bouncing ot the gauge 90.

It is also important to observe that the plane of the conveyor, FIG. 6, is approximately 20 to the horizontal, thereby shortening the interim space between the extracting cylinder and the conveyor compared to a conveyor path which would be strictly horizontal. Therefore the released sheet moves through less distance. There is no difficulty in re-establishing a strictly horizontal path, easily accomplished through an appropriate conveyor belt.

Regardless of the use to which the pocket feeder is put, the arrangement enables two sheets or signatures to be fed per cycle of revolution of the extracting cylinder so that in eifect there is always a sheet or signature on the extracting cylinder, one sheet in the process of being extracted while the other sheet is in the process of being released to the conveyor.

Hence while We have illustrated and described preferred embodiments of our invention it is to be understood that this is capable of variation and modification.

We claim:

1. In a dat gathering signature machine of the charac- 4 ter described for transferring signature sheets from a supply pocket to an assigned area of little tolerance in area limit on a conveyor, the conveyor moving in a predetermined plane, means affording a plurality of pockets above the conveyor to contain a supply of sheets, a transfer cylinder located between each pocket and the conveyor and supported for rotation about a predetermined axis, a plurality of gripper means on each cylinder for withdrawing a plurality of sheets successively from the related pocket during 360 of rotation of the cylinder and moving the sheets downward along an arcuate path to a releasing position near the bottom of the cylinder for release in a plane immediately above the conveyor path, and means for directing a blast of air under pressure against the upper side of the released sheet for forcing the released sheet onto the conveyor, said means comprising at least two juxtaposed air conducting tubes conforming substantially to the radius of the cylinder and extending from the release position together upward part way toward the related pocket, each tube having a plurality of openings therein, one tube being longer than the other so that the openings in the tubes overlap in a supplementary eiect at the area of release to retard drifting of the released sheet while the longer tube is solely effective on the released sheet beyond the area of release.

2. A machine according to claim 1 in which the assigned areas on the conveyor for successive sheets are defined by longitudinally spaced feeders each adapted to engage the trailing edge of a released sheet, the path of movement of a sheet from the pocket to the releasing position being such that the sheet falls partly on a feeder in advance of a feeder to which said released sheet is aS- signed.

3. A machine according to claim 2 having a register gauge at one side of the conveyor extending parallel to the path of the conveyor and serving as a stop for one of the side edges of a released sheet, the conveyor moving along a path which is inclined downwardly toward the register gauge.

References Cited UNITED STATES PATENTS 907,944 12/1908 Abrams 271-12 2,827,287 3/1958 Gross et al 271-12 UX 3,395,943 8/1968 Wilde et al 271-74 X 2,166,709 7/ 1939 Swanson 270-56 2,643,113 6/ 195 3 Williams 270-56 FOREIGN PATENTS 629,435 4/ 1936 Germany 271-74 EVON C. BLUNK, Primary Examiner B. H. STONER, IR., Assistant Examiner U.S. Cl. X.R.

270-54; 271-27, 71, 74, DIG. 2 

